1. Field of the Invention
The present invention relates to the controlled delivery of electrical power of proper polarity to one or more circuits of a vehicle that receives electrical power from two or more electrical bus lines of different polarity positioned along the pathway on which the vehicle travels to operate one or more circuits of the vehicle.
2. Description of Related Art
Vehicles, such as without limitation, a train, a people mover, and the like, which travel along a pathway and which receive electrical power from two or more electrical buses of opposite polarity positioned along said pathway for the operation of one or more circuits of the vehicle are well known in the art. Such pathways can be of any suitable and/or desirable form that facilitates the movement of rail and/or non-rail vehicles therealong, including, without limitation, a rail vehicle or tire-mounted vehicle (e.g., a people mover).
Heretofore, to avoid creating a short circuit between an electrical bus of one polarity and an electrical bus of another polarity when one pair of contacts of the vehicle moves from being in contact with the bus of the first polarity to the bus of the second polarity while a second pair of contacts of the vehicle are in contact with the electrical bus of the first polarity, switches or contactors within the vehicle were operated to electrically isolate the one or more circuits of the vehicle from the electrical buses until both pairs of contacts were in contact with an electrical bus of the same polarity.
A problem with isolating one or more circuits of the vehicle from a source of electrical power until both sets of vehicle contacts have completed moving from being in contact from the electrical bus of a first polarity to the electrical bus of a second polarity is that passengers are subjected to discomforting ride-quality concerns such as: loss of interior lights; a sudden change in air/heat circulation and associated sound; a sudden change to ride quality (a momentary jerk in motion), and the like. Examples of vehicle circuits that receive power from such electrical buses include interior lights; heating and air conditioning system; an electric motor of the vehicle utilized to drive the vehicle along the pathway, and the like.
Accordingly, it would be desirable to provide a system and method that enables circuits of the vehicle traveling along a pathway to receive a constant supply of proper polarity electrical power from two or more electrical buses of opposite polarity disposed along said pathway.